Liquid crystal cell and method of manufacture

ABSTRACT

A LC cell is manufactured by the method including the steps of: rubbing a first alignment layer coating a first substrate, such that the first alignment layer has a first pretilt angle associated therewith; exposing said second alignment layer coating a first substrste to light such that said second alignment layer has at least one second pretilt angle associated therewith; and providing a liquid crystal material between said first and second substrates. The materials for the first and second alignment layers include a polyimide and a polysiloxane based material.

BACKGROUND OF THE INVENTION

1. The present invention is related to a liquid crystal cell, moreparticularly to a liquid crystal cell which is including one substratecoated with rubbed alignment layer and the other substrate coated withphoto-aligned alignment layer, and the method for fabricating that.

2. Generally, the liquid crystal cell is comprising of two substratesand liquid crystal formed between these substrates, the liquid crystalcomprising anisotropic molecules. To provide an orderly alignment ofliquid crystal in the cell for the uniform brightness and the highcontrast ratio of the liquid crystal cell, convnetionally rubbing iscarried out on alignment layers coating substrate. The rubbing ismechanical firiction on the alignment layer so as to provide a pretiltof liquid crystal molecules defined by a pretilt angle and a pretiltangle direction. The pretilt angle refers a polar angle and the pretiltangle direction refers a azimuthal angle between the surface ofalignment layer and the pretilt.

3. The pretilt of a liquid crystal molecule adjacent a first alignmentlayer is called a first pretilt of a first alignment layer, and thepretilt of a liquid crystal molecule adjacent a second alignment layeris called a second pretilt of a second alignment layer. Thereby, thepretilt of a liquid crystal molecule in the midle of two layers isdetermed by the interaction between pretilts of the first and secondalignment layer.

4. The liquid crystal cell is classified a vertical aligned liquidcrystal cell and a horizontal aligned liquid crystal cell depending thepretilt angle. The vertical aligned liquid crystal cell typicallydefines a liquid crystal cell having a pretilt angle of an alignmentlayer larger than 60°, the horizontal algined liquid crystal celltypically refers a liquid crystal cell having a pretilt angle of analignment layer less than 5°.

5. There are several modes liquid crystal cell according torelationships between a first pretilt angle direction of a firstalignment layer and a second pretilt angle direction of a secondalignment layer facing the first substrate. If the first pretilt angledirection is perpendicular to the second alignment direction, it iscalled a twisted nematic(TN) mode liquid crystal cell. If they areparallel with each other, the liquid crystal cell is called anelectrically controlled birefringence (ECB) mode liquid crystal cell anda bend mode liquid crystal cell. In addition, it is called a In-PlaneSwitching (IPS) mode liquid crystal cell if a pretilt angle direction isshift depending on the voltafe.

6. A conventionally used liquid crystal display is mainly a twistednematic liquid crystal display (TNLCD), in which the transmittance isdependent according to the viewing angle at each gray level. Especially,while the transmittance is symmetrical in the horizontal direction, thetransmittance is asymmetrical in the vertical direction. Therefore, inthe vertical direction, the range with inverted image phenomenon isoccurred so that the vertical viewing angle becomes very limited.

7. To overcome said problems, a multi-domain TNLC cell such as atwo-domain liquid crystal cell, and a four-domain liquid crystal cell isintroduced. The multi-domain liquid crystal cell has a wider viewingangle by providing more than domains in each pixel, domains havingdifferent pretilts each other, so as to compensate the viewing angledependence of each domain.

8. The most popular process to obtain said multi-domain liquid crystalcell is mechanical rubbing process, as shown in FIG. 1. Rubbing isperformed mechanically on entire substrate 1 coated with alignment layer8 such as polyimide, so that microgrooves are formed on the surface ofthe alignment layer 8, as shown in FIG. 1a, and FIG. 1b. To divide twodomains in a pixel, in FIG. 1c and FIG. 1d, a photoresist 11 is coatedentire alignment layer 8 surface, and the photoresist 11 of one domainis removed by exposing light, reverse rubbing process is carried out onone domain as shown in FIG. 1e. The remained photoresist is removed byexposing light, then, two domains are provided on the substrate 1 asshown in FIG. 1f. In the two-domain liquid crystal cell obtainedthereby, the inversion of viewing angle is compensated by aforementionedprocess.

9. However, the rubbing process causes a dust particle and/or anelectrostatic discharge, so the yield is reduced and/or the substrate isdamaged. The manufacturing process becomes too complicated to applyindustry, because the process includes a photolithography which iscoating photoresist layer and removing a part of the layer by exposinglight, for dividing domains.

10. Therefore, it is a photo-alignment method that is introduced tosimplify alignment process as well as to prevent the damage ofsubstrate. The photo-alignment is the process in which a pretilt angledirection of alignment layer is given by the irradiation of linearlypolarized ultraviolet light. The alignment layer used in thephoto-alignment method is mainly including PVCN (polyvinyl cinnamate).When ultraviolet light is irradiated into the photo-aligned layercoating the substrate, it causes cyclo-addition between the cinnamoylgroups of cinnamic acid side chains that belong to differentphotopolymers. Thereby, the direction of the photopolymer configurationi.e., the pretilt of alignment layer is aligned uniformly.

11. One example of the photo-alignment method is disclosured as afollowing process. The photo-alignment method is comprising doubleexposure of linearly polarized ultraviolet light into a substrate coatedwith PVCN to determine a pretilt, the pretilt including an alignmentdirection, a pretilt angle direction and pretilt angle. First linearlypolarized ultraviolet light is perpendicularly irradiated into thealignment layer coating substrate so as to determine a plurality ofpretilt angle direction. Then, second linearly polarized light isobliquely irradiated into the alignment layer again, to determine apretilt angle and a pretilt angle direction. The pretilt angle andpretilt angle direction are obtained by controlling the second obliquedirection relative to the substrate coated with the alignment layer.

12. However, the photo-alignment method has problems that the process iscomplicated due to the double exposure and the pretilt angle is toosmall, for example, the obtained pretilt angles being approximately0.15°, 0.26° and 0.30° respectively when the oblique irradiation anglesare 30°, 45° and 60°. In addition, it takes long time to irradiate lightinto the alignment layer so total tact time is prolonged, as well, thealignment stability of photo-alignment method is weaker than that ofrubbing method.

SUMMARY OF THE INVENTION

13. An object of the present invention is to provide a liquid crystalcell having an alignment stability and a wilder viewing angle by simplyprocess and the fabrication method thereof.

14. To achieve the object mentioned above, the method for fabricatingthe liquid crystal cell of the present invention is comprising thefollowing steps of: providing a first alignment layer on a firstsubstrate; rubbing said first alignment layer such that said firstalignment layer has a first pretilt angle associated therewith;providing a second alignment layer on a second substrate; exposing saidsecond alignment layer to light such that said second alignment layerhas at least one second pretilt angle associated therewith; andproviding a liquid crystal material between said first and secondsubstrates.

15. The first alignment layer is comprising polyimide, but the secondalignment layer is comprising photopolymers, the photo-polymersincluding polysiloxane based materials. The pretilt angle of thisinvention is controlled depending upon the photo-energy of theultraviolet light irradiating.

16. To determined the second pretilt, this invention includes doubleirradiation of this invention. The double irradiation is comprisingsteps of: irradiating polarized light in the perpendicular direction tothe second alignment layer and irradiating unpolarized light in theoblique direction to the second alignment layer. In this steps, thelatter step can be prior to the former.

17. Another method for determining the second pretilt in this inventionis using flowing effect. The method is comprising the steps of:irradiating polarized light in the perpendicular direction to the secondsubstrate so as to determine a second pretilt angle and two pretiltangle direction; and injecting liquid crystal materials between saidfirst substrate and said second substrate in the perpendicular directionto the polarized direction of the light so as to select a pretilt angleand a second pretilt angle direction.

18. These and other objects and advantages of the present invention willbecome clear from the following description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

19.FIG. 1 is showing a conventional reverse-rubbing process.

20.FIG. 2 is showing a cross-sectional view of liquid crystal cellaccording to this invention.

21.FIG. 3 is showing a photo-irradiation device used for photo-alignmentprocess.

22.FIG. 4 is a graph illustrating the relationship between thephoto-energy of ultraviolet light and the pretilt angle of thephoto-aligned layer formed with polysiloxane based materials.

23.FIG. 5 is one process for fabricating a liquid crystal cell accordingto this invention.

24.FIG. 6 is another process for fabricating a liquid crystal cellaccording to this invention.

25.FIG. 7 is a showing a cross-sectional view of a TN mode liquidcrystal cell according to this invention

26.FIG. 8 is a showing a cross-sectional view of a ECB mode liquidcrystal cell according to this invention.

27.FIG. 9 is a showing a cross-sectional view of a bend mode liquidcrystal cell according to this invention.

28.FIG. 10 is a showing a cross-sectional view of a IPS mode liquidcrystal cell according to this invention.

29.FIG. 11 is a showing one process for fabricating a multi-domainliquid crystal cell according to this invention.

30.FIG. 12 is another process for fabricating a multi-domain liquidcrystal cell according to this invention.

31.FIG. 13 is another process for fabricating a multi-domain liquidcrystal cell according to this invention.

32.FIG. 14 is another process for fabricating a multi-domain liquidcrystal cell according to this invention.

DETAILED DESCRIPTION OF INVENTION

33.FIG. 2 is a drawing showing the liquid crystal cell, and 1 and 2indicate a first substrate and a second substrate of the liquid crystalcell, respectively. The first substrate 1 is coated with the firstalignment layer 8 formed with polyimide and is rubbed so as to determinea first pretilt defined a first pretilt angle and a first pretilt angledirection. The second substrate 2 is coated with the second alignmentlayer 9. The material for the second alignment layer 9 includesphoto-polymers such as polysiloxane based materials. Polysiloxanecinnamate, one of the polysiloxane based materials have followingstructural formulas: polysiloxane cinnamate I:

34. Z can be selected from the group consisting of OH, CH₃ or frommixtures thereof,

35. m=10-100,

36. l=1-11,

37. L=0 or 1,

38. K=0 or 1,

39. X, X₁, X₂, Y═H, F, Cl, CN, CF₃, C_(n)H_(2n+1) or OC_(n)H_(2n+1)wherein n can be from 1 to 10, or from mixtures thereof;

40. polysiloxane cinnamate II:

41. Z can be selected from the group consisting of OH, CH₃ ⁻or frommixtures thereof,

42. m=10-100,

43. l=1-11,

44. L=0 or 1,

45. K=0 or 1,

46. X, X₁, X₂, Y═H, F, Cl, CN, CF₃, C_(n)H_(2n+1) wherein n can be from1 to 10, or from mixtures thereof.

47. Then, the second substrate 2 coated with a second alignment layer 9is exposed ultraviolet light by a photo-irradiation device in FIG. 3.The device includes the lamp 3 generating ultraviolet light, a lens 4and a polarizer 5 linearly polarizing the ultraviolet light from lamp 3.To irradiate ultraviolet light into the alignment layer 9 of thesubstrate 2, the ultraviolet light generated from the lamp 3 is passedthe lens 4 and linearly polarized through polarizer 5, then theultraviolet light is irradiated into the alignment layer 9 coatingsubstrate 2. The lamp 3 is the Mercury (Hg) lamp having the wave lengthof 365 nm.

48. In that time, the pretilt angle formed on the alignment layer 9 canbe controlled by photo-energy. When ultraviolet light is perpendicularlyirradiated into the substrate 2 coated with alignment layer 9 ofpolysiloxane based materials, the pretilt angle of the alignment layer 9surface is controlled in a broad range according to the photo-energy ofthe ultraviolet light, as shown in FIG. 4. Referring to this figure, thepretilt angle can be controlled depending the photo-energy irradiatedinto the alignment layer 9 (the wavelength of ultraviolet light is 350nm). The pretilt angle is exponentially get down according to thephoto-energy of ultraviolet light to at almost 0° at 6,000 mJ/cm.

49. The vertical aliged liquid crystal cell can be fabricated byadopting photo-energy less than 2,000 mJ/cm², and the horizontal alignedliquid crystal cell can be fabricated by adopting photo-energy more than5,000 mJ/cm².

50.FIG. 5 is showing one embodiment of a process for fabricating aliquid crystal cell which comprises a first substrate, a secondsubstrate and a liquid crystal layer injected therebetween. The firstsubstrate 1 coated with a first alignment layer 8 is mechanically rubbedto determine a pretilt, the pretilt meaning a pretilt angle and apretilt angle direction, as shown in FIG. 5a and FIG. 5b.

51. The polarized light is irradiated in the perpendicular directiononto the second substrate 2 coated with a second alignment layer 9 so asto determine a second pretilt angle and two pretilt angle directionfacing each other as shown in FIG. 5c and FIG. 5d. To select one pretiltangle direction, nonpolarized light is irradiated in the obliquedirection onto the alignment layer 9 on the substrate 2 so as todetermine a second pretilt oriented with one pretilt angle direction. InFIG. 5f, attaching the first substrate 1 and the second substrate 2,liquid crystal materials are injected between two substrates 1,2 so asto align uniformly by the stable anchoring provided by the firstpretilt.

52. In addition, it is also possible that the oblique-irradiation can becarried out prior to the perpendicular irradiation in this embodiment.

53.FIG. 6 is showing another embodiment of a process for fabricating aliquid crystal cell which comprises a first substrate, a secondsubstrate and a liquid crystal layer injected therebetween. The firstsubstrate 1 is coated with a first alignment layer 8 is mechanicallyrubbed to determine a pretilt, the pretilt meaning a pretilt angle and apretilt angle direction, as shown in FIG. 6a and FIG. 6b.

54. The polarized light is irradiated in the perpendicular directioninto the second substrate 2 coated with a second alignment layer 9 so asto determine a second pretilt angle and two pretilt angle directionfacing each other as shown in FIG. 6c and FIG. 6d. To select one pretiltangle direction, this embodiment adopts the flowing effect of liquidcrystal materials in which the pretilt angle direction is determinedaccording to the flowing direction of liquid crystal material flown asshown in FIG. 6e, FIG. 6f. Attaching the first substrate 1 havinguni-pretilt determined alignment layer 8 by rubbing and second substrate2 having two pretilts oriented with two pretilt angle directionsdetermined a photo-aligned layer 9, then liquid crystal materials areinjected between two substrates. By the flowing effect of liquid crystalmaterials, the liquid crystal materials adjacent the second alignmentlayer 9 is aligned uni-second pretilt angle direction by a singleexposure.

55. There are several mode of liquid crystal cell depending theconfiguration between the first pretilt angle direction and the secondpretilt angle direction determined by either abovementioned process.

56.FIG. 7 is reffering a TN mode liquid crystal cell. FIG. 7a and FIG.7b are showing a vertical aligned liquid crystal cell controllingdepending upon the voltage. FIG. 7c and FIG. 7d are showing a horizontalaligned liquid crystal cell.

57.FIG. 8 is reffering a ECB mode liquid crystal cell. FIG. 8a and FIG.8b are showing a vertical aligned liquid crystal cell controllingdepending upon the voltage. FIG. 8c and FIG. 8d are showing a horizontalaligned liquid crystal cell.

58.FIG. 9 is reffering a bend mode liquid crystal cell. FIG. 9a and FIG.9b are showing a vertical aligned liquid crystal cell controllingdepending upon the voltage. FIG. 9c and FIG. 9d are showing a horizontalaligned liquid crystal cell.

59.FIG. 10 is reffering a IPS mode liquid crystal cell in which theliquid crystal molecules are shift in plane dependind on the voltage.

60. This invention can be applied in a multi-domain liquid crystal cellto provide wider viewing angle. Some embodiments of process formanufacturing the multi-domain liquid crystal cell are in FIG. 11, FIG.12, FIG. 13 and FIG. 14.

61.FIG. 11 is showing one embodiment of this invention to provide amulti-domain liquid crystal cell in which the first alignment layer 8 isprovided a first pretilt by mechanically rubbing, and the secondalignment layer 9 is provided two pretilts in two domains by using thelight.

62.FIG. 11a and FIG. 11b is showing the rubbing process to provide afirst pretilt on the alignment layer 8 with low pretilt angle, almost0°. FIG. 11c-FIG. 11f are showing the process for forming two secondpretilts on two domains of the second alignment layer 9 with a highphoto-energy to provide low pretilt angle less than 5°. The polarizedlight is irradiated in the perpendicular direction onto the secondalignment layer 9 so as to determined a second pretilt angle and twopretilt angle direction, as shown in FIG. 11d. To select a first pretiltangle direction for a first domain I, the nonpolarized light isirradiated in the first oblique direction to the second substrate 2 inwhich a second domain II is covered with the mask 10. Thereby, the 2-1thpretilt is formed on a first domain I, the 2-1th pretilt defined asecond pretilt angle and a first pretilt angle direction, as shown inFIG. 11e.

63. To select a 2-2th pretilt angle direction for a second domain II,the mask 10 covering the second domain II is moved to the first domainI. The nonpolarized light is irradiated in the second oblique directionto the second substrate 2 in which a first domain I is covered with themask 10. Thereby, the 2-2th pretilt is formed on a second domain II, asshown in FIG. 11f, the 2-2th pretilt meaning a second pretilt angle anda second pretilt angle direction.

64. Assembling the first substrate 1 and the second substrate 2, liquidcrystal materials are injected between two substrates 1,2. The moleculesof liquid crystal materials are arranged in the different directionbetween domains as shown in FIG. 11g depending the second pretilts.

65. Thereby, the viewing angle is compensated by differently aligningthe liquid crystal molecules according to domains so as to get a widerviewing angle liquid crystal cell.

66. In this embodiment, the two-domain liquid crystal cell is possibleto obtain multi-domain liquid crystal cell without photolithograpy. Inaddition, the alignment stability is provided by the first pretilt.

67.FIG. 12 is showing another embodiment of this invention to provide avertical aligned mode multi-domain liquid crystal cell in which thefirst alignment layer 8 is provided a first pretilt by mechanicallyrubbing, and the second alignment layer 9 is provided two pretilts intwo domains by using the light.

68.FIG. 12a and FIG. 12b is showing the rubbing process to provide afirst pretilt on the alignment layer 8 with high pretilt angle largerthan 60°. FIG. 12c- FIG. 12f are showing the process for forming twosecond pretilts on two domains of the second alignment layer 9 with alow photo-energy to provide high pretilt angle less than 60°. Thepolarized light is irradiated in the perpendicular direction onto thesecond alignment layer 9 so as to determined a second pretilt angle andtwo pretilt angle direction, as shown in FIG. 12d. To select a firstpretilt angle direction for a first domain I, the nonpolarized light isirradiated in the first oblique direction to the second substrate 2 inwhich a second domain II is covered with the mask 10. Thereby, the 2-1thpretilt is formed on a first domain I, the 2-1th pretilt defined asecond pretilt angle and a first pretilt angle direction, as shown inFIG. 12e.

69. To select a 2-2th pretilt angle direction for a second domain II,the mask 10 covering the second domain II is moved to the first domainI. The nonpolarized light is irradiated in the second oblique directionto the second substrate 2 in which a first domain I is covered with themask 10. Thereby, the 2-2th pretilt is formed on a second domain II, asshown in FIG. 12f, the 2-2th pretilt meaning a second pretilt angle anda second pretilt angle direction.

70. Assembling the first substrate 1 and the second substrate 2, liquidcrystal materials are injected between two substrates 1, 2. Themolecules of liquid crystal materials are arranged in the differentdirection between domains as shown in FIG. 12g depending the secondpretilts. This vertical algined liquid crystal cell has a bend mode inthe first domain I and a ECB mode in the second domain II.

71. Thereby, the viewing angle is compensated by differently aligningthe liquid crystal molecules according to domains so as to get a widerviewing angle liquid crystal cell.

72. In this embodiment, the two-domain liquid crystal cell isaccomplished by low photo-energy so it is possible to obtainmulti-domain liquid crystal cell without photolithograpy. In addition,the alignment stability is provided by the first pretilt.

73.FIG. 13 is showing another embodiment of process for multi-domainliquid crystal cell.

74.FIG. 13a and FIG. 13b is showing the rubbing process to provide a1-1th pretilt and 1-2th pretilt on a first domain I and a second domainII of the first substrate 1 with different pretilt angle, such as 1-1thpretilt angle is larger than 1-2th pretilt angle. The alignment layerfor dividing domain is shown in FIG. 13a, an organic alignment layer 8Ais covered with an inorganic alignment layer 8B on the first substrate1. In the organic alignment layer 8A, pretilt angle is formed largerthan in the inorganic alignment layer 8B. Thus, the 1-1ith pretilt isdefined a low 1-1th pretilt angle and a first pretilt angle direction,and the 1-2th pretilt is defined a high 1-2th pretilt angle a firstpretilt angle direction.

75.FIG. 13c-FIG. 13d are showing the process for two domained the secondsubstrate 2 with dividing two pretilts by differing two pretilt angles.The substrate 2 coated with a second alignment layer 9 is covered with amask 10 comprising of a transparent part for a first domain I and asemi-transparent part for a second domain II. The polarized light isirradiated in the perpendicular direction onto the second substrate soas to determined a high 2-1th pretilt angle, a second alignmentdirection and two second pretilt angle directions on a first domain I,and a low 2-2th pretilt angle and two second pretilt angle directions ona second domain II. To select a second pretilt angle direction for afirst domain I and a second domain II, the nonpolarized light isirradiated in the oblique direction to the second substrate 2. Thereby,the 2-1th pretilt and 2-2th pretilt are formed on a first domain I and asecond domain II, respectively, the 2-1th pretilt meaning a high 2-1pretilt angle and a second pretilt angle direction, and the 2-1thpretilt meaning a low 2—2 pretilt angle and a second pretilt angledirection, as shown in FIG. 13e.

76. Assembling the first substrate 1 and the second substrate 2, liquidcrystal materials are injected between two substrates 1,2. The moleculesof liquid crystal materials are aligned in the different directionbetween domains as shown in FIG. 13f depending the pretilt angles.

77. Thereby, the viewing angle is compensated by differently aligningthe liquid crystal molecules according to domains so as to get a widerviewing angle liquid crystal cell.

78. In this embodiment, the two-domain liquid crystal cell is possibleto obtain multi-domain liquid crystal cell without photolithograpy. Inaddition, the alignment stability is provided by the rubbed firstalignment.

79.FIG. 14 is showing a process for fabricating four-domain liquidcrystal cell. A two-domain first substrate 1 is prepared by the reverserubbing, as shown in FIG. 14a, FIG. 14b and FIG. 14c. The Four-domainsecond substrate 2 is prepared by changing the photo-irradiatingdirection, as shown in FIG. 14d-FIG. 14i.

80. Attaching two substrates 1,2, liquid crystal materials are injectedbetween two substrates 1,2. The, the viewing angle is compensated bydifferently aligning the liquid crystal molecules according to eachdomain, as shown in FIG. 14g so as to get a wider viewing angle liquidcrystal cell.

81. This invention can be adopted to the various mode liquid crystalcells such as a TN mode, a ECB mode, a bend mode, and a IPS mode bycontrolling the alignment direction.

82. In this invention, it is possible to provide alignment stability byrubbed first alignment layer, and to increase the yield by aligningusing light instead of rubbing so as to eliminating damages caused byrubbing process.

83. In addition, the multi-domain liquid crystal cell can be obtained bysimply process without a photolithograpy for reverse rubbing.

84. It is to be understood that the form of the present invention hereinshow and described is to be taken as a preferred example of the same andthat various application such as the change the photo-irradiation order,may be resorted to without departing from the spirit of the presentinvention or the scope of the subjoined claims.

What is claimed is:
 1. A method of manufacturing a liquid crystaldisplay, comprising the steps of: providing a first alignment layer on afirst substrate; rubbing said first alignment layer such that said firstalignment layer has a first pretilt angle associated therewith;providing a second alignment layer on a second substrate; exposing saidsecond alignment layer to light such that said second alignment layerhas at least one second pretilt angle associated therewith; andproviding a liquid crystal material between said first and secondsubstrates.
 2. A method in accordance with claim 1 , wherein said firstalignment layer comprises polyimide.
 3. A method in accordance withclaim 1 , wherein said second alignment layer comprises polysiloxanebased materials.
 4. A method in accordance with claim 1 , wherein saidlight includes linearly polarized light.
 5. A method in accordance withclaim 1 , wherein said exposing step further comprises the steps of:generating unpolarized light; and transmitting said unpolarized lightthrough a polarizer to generate said lincarly polarized light.
 6. Amethod in accordance with claim 5 , wherein said linearly polarizedlight includes linearly polarized ultraviolet light.
 7. A method inaccordance with claim 1 , wherein said light is incident substantiallyperpendicular to said second alignment layer.
 8. A method in accordancewith claim 1 , wherein said light comprises ultraviolet light.
 9. Amethod in accordance with claim 1 , wherein said exposing step includesa single exposure to said light.
 10. A method in accordance with claim 1, wherein a plurality of pretilt angles are associated with said secondalignment layer after said exposing step, said plurality of pretiltangles being oriented in respective pretilt directions, said providingstep further comprising the step of injecting said liquid crystalmaterial between said first and second substrates so as to select onesof said plurality of pretilt angles oriented in a single direction. 11.A method in accordance with claim 7 , wherein said photo-incidation isfurther comprising the step of exposing additional light to select onesof said plurality of pretilt angles oriented in a single direction. 12.A method in accordance with claim 11 , wherein said additional lightcompries unpolarized light.
 13. A method in accordance with claim 12 ,wherein said unpolarized additional light is obliquely incident to thesecond alignment layer.
 14. A method in accordance with claim 1 ,wherein said exposing step is comprising the steps of; exposing saidsecond alignment layer to a polarized light in the perpendiculardirection; and exposing said second alignment layer to a nonpolarizedlight in the oblique direction.
 15. A method in accordance with claim 1, wherein said exposing step is comprising the steps of; exposing saidsecond alignment layer to a nonpolarized light in the oblique direction;and exposing said second alignment layer to a polarized light in theperpendicular direction.
 16. A method in accordance with claim 1 ,wherein said exposing steps further comprises the steps of: exposingsaid second alignment layer to a first light such that a plurality ofpretilt angles are associated with said second alignment layer, saidplurality of pretilt angles being oriented in respective pretiltdirections, exposing a first portion of said second alignment layer to asecond light so as to select ones of said pretilt angles associated withsaid first portion oriented in a first direction; and exposing a secondportion of said second alignment layer to a third light so as to selectones of said pretilt angles associated with said second portion orientedin a second direction.
 17. A method in accordance with claim 16 ,wherein said first light includes linearly polarized light.
 18. A methodin accordance with claim 16 , wherein said first light is incidentsubstantially perpendicular to a surface of said second alignment layer.19. A method in accordance with claim 16 , wherein said second lightand/or said third light include/includes unpolarized light.
 20. A methodin accordance with claim 19 , wherein said second light and/or saidthird light are/is incident obliquely to said surface of said secondalignment layer.
 21. A method in accordance with claim 1 , furthercomprising the steps of: providing a third alignment layer on a portionof said first alignment layer; rubbing said third alignment layer suchthat said third alignment layer has a third pretilt angle associatedtherewith.
 22. A method in accordance with claim 21 , wherein said thirdalignment layer has a pretilt angle forming characteristics differingthan the first alignment layer's.
 23. A method in accordance with claim21 , wherein said third pretilt angle has a magnitude greater than saidfirst pretilt angle.
 24. A method in accordance with claim 1 , furthercomprising the steps of: exposing a first portion of said secondalignment layer to a first dose of a first light such that a firstplurality of pretilt angles having respective pretilt directions areassociated with said first portion of said second alignment layer, andexposing a second portion of said second alignment layer to a seconddose of said first light such that a second plurality of pretilt angleshaving respective pretilt directions are associated with said secondportion of said second alignment layer.
 25. A method in accordance withclaim 24 , further comprising the steps of: exposing said first portionof said second alignment layer to a first dose of a second light toselect ones of said pretilt angles associated with said first portion ofsaid second alignment layer; and exposing said second portion of saidsecond alignment layer to a second dose of said second light to selectones of said pretilt angles associated with said second portion of saidsecond alignment layer.
 26. A method in accordance with claim 24 ,wherein said first light includes linearly polarized light.
 27. A methodin accordance with claim 28 , wherein said first light is incidentsubstantially perpendicular to said surface of said second alignmentlayer.
 28. A method in accordance with claim 24 , wherein said firstplurality of pretilt angles each have a magnitude greater than amagnitude of each of said second plurality of pretilt angles.
 29. Amethod in accordance with claim 25 , wherein said second light includesunpolarized light.
 30. A method in accordance with claim 25 , whereinsaid second light is incident obliquely to said surface of said secondalignment layer.
 31. A method in accordance with claim 24 , wherein saidfirst light is supplied to said second alignment layer through a platehaving a first part aligned with said first portion of said substrateand having a first transmissivity, and a second part aligned with saidsecond portion of said second alignment layer and having a secondtransmissivity.
 32. A method in accordance with claim 25 , wherein saidsecond light is supplied to said second alignment layer through a platehaving a first part aligned with said first portion of said secondalignment and having a first transmissivity, and a second part alignedwith said second portion of said second alignment layer and having asecond transmissivity.
 33. A method in accordance with claim 1 , whereinsaid exposure step further comprises the steps of: exposing a firstportion of said second alignment layer to a first light such that afirst pretilt angle oriented in a first direction is associated withsaid first portion of said second alignment layer; exposing a secondportion of said second alignment layer to a second light such that asecond pretilt angle oriented in a second direction is associated withsaid second portion of said second alignment layer, exposing a thirdportion of said second alignment layer to a third light such that athird pretilt angle oriented in a third direction is associated withsaid third portion of said second alignment layer; and exposing a fourthportion of said second alignment layer to a fourth light such that afourth pretilt angle oriented in a fourth direction is associated withsaid fourth portion of said second alignment layer.
 34. A method inaccordance with claim 33 , wherein at least ones of said lights includesunpolarized light, the lights including the first light, the secondlight, the third light, and fourth light.
 35. A method in accordancewith claim 34 , wherein at least ones of said lights is incidentobliquely to said surface of said second alignment layer the lightsincluding the first light, the second light, the third light, and fourthlight.
 36. A method in accordance with claim 1 , wherein the exposingstep is comprising the steps of: exposing a first portion of said secondalignment layer to a first polarized light in the first perpendiculardirection; and exposing a second portion of said second alignment layerto a second polarized light in the second perpendisular direction.
 37. Amethod in accordance with claim 36 , wherein the exposing step isfurther comprising the steps of: exposing a first portion of said secondalignment layer to a first unpolarized light in the first obliquedirection; and exposing a second portion of said second alignment layerto a second unpolarized light in the second oblique direction.
 38. Amethod in accordance with claim 36 , wherein the exposing step isfurther comprising the steps of: exposing a first area of a firstportion of said second alignment layer to a first unpolarized light in afirst oblique direction; exposing a second area of a first portion ofsaid second alignment layer to a second unpolarized light in a secondoblique directionand: exposing a first area of a second portion of saidsecond alignment layer to a third unpolarized light in a third obliquedirection: and exposing a second area of a second portion of said secondalignment layer to a fourth unpolarized light in a fourth obliquedirection.
 39. A method of manufacturing a liquid crystal display,comprising the steps of: coating a first substrate with a firstalignment layer; rubbing said first alignment layer to impart a firstalignment direction, a first pretilt angle direction and a first pretiltangle magnitude; coating a second substrate with a second alignmentlayer; exposing said second alignment layer to impart a second alignmentdirection, a plurality of second pretilt angles each having a secondpretilt angle magnitude and oriented in a plurality of pretilt angledirection; and injecting liquid crystal material between said first andsecond substrates to select those of said plurality of pretilt anglesoriented in one of said pretilt angle directions.
 40. A method ofmanufacturing a liquid crystal cell in accordance with claim 39 ,wherein said first alignment layer includes polyimide.
 41. A method ofmanufacturing a liquid crystal cell in accordance with claim 39 ,wherein said second alignment layer includes a polysiloxane basedmaterial.
 42. A method of manufacturing a liquid crystal cell inaccordance with claim 39 , wherein during said exposing step, said lightis incident substantially perpendicular to said second alignment layer.43. A method of manufacturing a liquid crystal cell in accordance withclaim 39 , wherein said light comprises ultraviolet light.
 44. A methodof manufacturing a liquid crystal cell in accordance with claim 43 ,wherein said ultraviolet light comprises linearly polarized ultravioletlight.
 45. A method of manufacturing a liquid crystal cell in accordancewith claim 39 , wherein said exposing step includes a single exposure ofsaid second alignment layer to said light.
 46. A method of manufacturinga liquid crystal cell in accordance with claim 39 , wherein said firstpretilt angle direction is different from said second pretilt angledirection.
 47. A liquid crystal display device comprising: a firstsubstrate; a rubbed layer provided on said first substrate; a secondsubstrate; a photo-aliged layer provided on said second substrate; andliquid crystal material provided between said first and secondsubstrates.
 48. A liquid crystal display device in accordance with claim47 , wherein said rubbed layer comprises polyimide.
 49. A liquid crystaldisplay device in accordance with claim 47 , wherein said photo-aligedlayer comprises a polysiloxane based material.
 50. A liquid crystaldisplay device in accordance with claim 47 , wherein first molecules ofsaid liquid crystal material adjacent said rubbed layer are aligned in afirst direction, the first direction having a first pretilt angle and afirst pretilt angle direction associated with said rubbed layer.
 51. Aliquid crystal display device in accordance with claim 47 , whereinsecond molecules of said liquid crystal material adjacent saidphoto-aligned layer are aligned in a second direction, the seconddirection having a second pretilt angle and a second pretilt angledirection associated with said photo-aliged layer.
 52. A liquid crystaldisplay device in accordance with claim 47 , wherein said first pretiltangle and/or said second pretilt angle are/is larger than 60°.
 53. Aliquid crystal display device in accordance with claim 52 , wherein saidfirst pretilt angle and/or said second pretilt angle are/is 75°-87°. 54.A liquid crystal display device in accordance with claim 47 , whereinsaid first pretilt angle direction is substantially parrallel with saidsecond pretilt angle direction.
 55. A liquid crystal display device inaccordance with claim 47 , wherein said first pretilt angle direction isdifferent with said second pretilt angle direction.
 56. A liquid crystaldisplay device in accordance with claim 55 , wherein said first pretiltangle direction is substantially perpendicular to said second pretiltangle direction.
 57. A liquid crystal display device in accordance withclaim 55 , wherein said first pretilt angle direction is substantiallyanti-parallel to said second pretilt angle direction.
 58. A liquidcrystal display device in accordance with claim 47 , wherein pluralitiesof liquid crystal molecules are provided adjacent respective portions ofsaid photo-aligned layer, each plurality of liquid crystal moleculeshaving a corresponding pretilt angle and pretilt direction.